Tool holders used in conjunction with boring tool compensators typically utilize an internal adjustment member for positioning a cutting edge to account for normal wear. These devices employ radially extending internal arms which drive cutting edges in accordance with axial drawbar motion. Devices of this sort, however, result in imbalanced tools and frequently encounter problems such as chattering and poor repeatability.
One type of known tool holder incorporating the beforementioned features is discussed in Walker, U.S. Pat. No. 3,753,624, issued on Aug. 21, 1973 and is commonly assigned to the same assignee as the subject invention GTE Corporation. Walker discloses a tool holder which provides a tool shank supported within a housing by a forward pivotal support and an elastic rearward support. An axially oriented drawbar with a camming surface pivots the shank at the forward most portion of the tool holder by overcoming the resilient force of the rearward support. By moving the drawbar axially, the camming surface stresses the resilient support causing the central shaft member to tilt radially outward. The attached cutting member is thereby radially displaced.
When sufficient force is applied to the cutting edge during normal cutting operation, the resilient force at the rear portion of the shank can be overcome resulting in chattering. Increasing the size of the support, however, limits the application of the tool to larger bore sizes. A tool holder which permits radial adjustment by automated means without chattering and which is adaptable for use in small bore is therefore a desirable advancement in the art of rotational cutting tool holders.
Accordingly, it is a further object of the present invention to provide a highly precise tool holder which allows for automated adjustment for cutting edge wear while at rest or during operation.
Another object of the present invention is to provide a tool holder which allows for radial adjustment to compensate for edge wear by means which are adaptable for use in narrow bores.
Another object is to provide automated adjustment for edge wear by axial drawbar motion where a reduced drive force is employed.
A further object is to provide a method for cutting edge adjustment which is simple to operate and easy to manufacture. Other objects will become apparent to those skilled in the art upon review of the following drawings, description, and claims.